Many impartant practical and mathematical applications involve comparing quantities of one kind or another; it is impoartant to know which method to use and how we should use them.
Essential question
Which comparing strategies work best in which situations?
6.1
Write a paragraph to help someone younger than you understand how the size of the T-Rex compares to the size of a human. Be very specific about the comparisons you are making.
T-Rex is 6 meters tall. You are about 1 meter tall. So a T-Rex is as tall as 6 of you. A T-Rex weighs 8100 kg. You weigh around 30 kg. So, a T-Rex is as heavy as 270 of you. That is, there has to be 270 of you to weigh as heavy as a T-Rex.
Now, a "larger than average" human being is 2 meters tall. So a T-Rex is as tall as 3 of average human beings. Most human beings are 80 kg average. So a T-Rex is as heavy as almost 100 of you. Do you now understand, how big a T-Rex is?
6.1 Follow-Up
1. Suppose an infant T-Rex was the same height as the human described in this problem and was similar to an adult T-Rex. What would be the scale factor between a grown T-Rex and an infant T-Rex?
The scale factor between a grown T-Rex and an infant T-Rex would be 3:1. The infant T-Rex will be 1/3 of an adult T-Rex.
2. How long were the incisors of this young T-Rex?
The incisors of this young T-Rex would be 1/3 of 15 cm. The young T-Rex's incisors would be 5 cm.
3. How long was the skull of this young T-Rex?
The length of the skull of this young T-Rex would be 1/3 of 1 m. Its skull would be around 33cm.
Jan. 25th 2010
Math 7B
The Big Idea
Many impartant practical and mathematical applications involve comparing quantities of one kind or another; it is impoartant to know which method to use and how we should use them.
Essential question
Which comparing strategies work best in which situations?
6.1
Write a paragraph to help someone younger than you understand how the size of the T-Rex compares to the size of a human. Be very specific about the comparisons you are making.
T-Rex is 6 meters tall. You are about 1 meter tall. So a T-Rex is as tall as 6 of you. A T-Rex weighs 8100 kg. You weigh around 30 kg. So, a T-Rex is as heavy as 270 of you. That is, there has to be 270 of you to weigh as heavy as a T-Rex.
Now, a "larger than average" human being is 2 meters tall. So a T-Rex is as tall as 3 of average human beings. Most human beings are 80 kg average. So a T-Rex is as heavy as almost 100 of you. Do you now understand, how big a T-Rex is?
6.1 Follow-Up
1. Suppose an infant T-Rex was the same height as the human described in this problem and was similar to an adult T-Rex. What would be the scale factor between a grown T-Rex and an infant T-Rex?
The scale factor between a grown T-Rex and an infant T-Rex would be 3:1. The infant T-Rex will be 1/3 of an adult T-Rex.
2. How long were the incisors of this young T-Rex?
The incisors of this young T-Rex would be 1/3 of 15 cm. The young T-Rex's incisors would be 5 cm.
3. How long was the skull of this young T-Rex?
The length of the skull of this young T-Rex would be 1/3 of 1 m. Its skull would be around 33cm.